The weather is warm and summery and the garden is full of colour. When we get to September our thoughts, and the shelves at Nags Hall, will be full of spring-flowering bulbs.
But before we get to that there is a short period when we should be planting other bulbs – those rather special, autumn-flowering bulbs. These are often overlooked by gardeners and there is the additional problem that because they bloom in autumn, from September to November, they need to be planted now and they are not in stock for long!
They can be planted in the next few weeks and they will start to bloom in a month or so. Early planting is important because the dry bulbs will start to sprout in the packs before they are planted and if they have long shoots already showing it can make planting tricky! This ability to grow even before they are planted is something of a party trick with colchicums which are often sold primarily because you can leave them on the windowsill (indoors) and they will produce lots of blooms from the dry bulb.
There are many different autumn-flowering bulbs including cyclamen but these are best planted as growing plants so I will leave them for now and will discuss them next week. Of the rest, I will mention my favourites: autumn crocus, nerines and colchicums.
Colchicum
These are often called autumn crocus but that is a confusing name and I would like to stop it being used – you will see why later. Either call them meadow saffron or, better still colchicums!
Colchicums have large bulbs and the flowers are produced in large numbers from each. They prefer a spot in the garden in sun or light shade in rich soil. They are not too fussy about soil and position. In the wild they grow in moist meadows. A few weeks after planting they will show their large and attractive flowers, usually in September and early October. They eventually make large clumps and the blooms only grow about 20cm high. They are lovely around shrubs and can even be grown in grass, though mowing regimes will have to be adapted to fit in with the flowers and foliage.
The flowers emerge before the leaves but spring brings a great tussock of thick, shiny leaves. They are not unattractive but they are large and they will swamp smaller plants. So although the flowers may look lovely growing through low-growing alpines and front-of-the-border plants, the leaves will swamp small plants. The leaves turn yellow and brown in May and can be a nuisance and they die down and need to be pulled up in July.
Bulbs are not cheap but it is best to plant three or more in a clump, about 10cm deep and 15-20cm apart. They should last for many years and even decades.
Autumn crocus
And then there are the true autumn crocus. These are real crocus just like the spring kinds. But they produce their flowers in autumn and then their leaves in spring. The most commonly available is the saffron crocus (Crocus sativus). Although the idea of growing your own saffron is appealing, it can be a tricky plant to please, needing well-drained soil and lots of sun and you need an awful lot of flowers to get enough saffron for your paella. You need about 150 flowers to produce 1 gram of dry saffron.
The best for garden display is Crocus speciosus. Often available in several named forms, all have large, sweetly scented flowers in shades of lilac and lavender. They pierce the soil or lawn with thin buds and open in the sunshine. They are very effective in lawns but you must note when the first buds appear and stop mowing the area and you must let the foliage grow in spring too. I plant some spring crocus with them which marks the areas where they grow. Each corm produces one to two flowers and it is best to be very generous with your planting. Put in at least 20 in a patch, planting 3-5cm deep and apart.
The contrast of the sparkling, fresh flowers against the trimmed lawn speckled with fallen autumn leaves is really delightful.
Nerines
Of all the autumn bulbs, nerines reward patience. Although there are many kinds and not all are hardy, Nerine bowdenii and its clan are fully hardy and among the most remarkable of all the plants that have come from South Africa to grace our gardens. The shocking pink flowers are all the more beautiful for being produced so late in the season, usually into October.
You can buy and plant bulbs now and they should bloom in a month or two but nerines dislike being dug up and disturbed so do not be disheartened if flowering this autumn is not quite what you expect.
Buy at least five bulbs and plant them in a spot that is dry and sunny. Often the best clumps are in otherwise barren front gardens, surrounded by concrete and against a sunny wall! Plant them about 10cm apart and with the top of the bulbs at soil level. Then let them get crowded – they usually bloom best when jostling for space. They produce strappy leaves in spring which die down in late summer before the flowers emerge.
The flowers also make good cut flowers.
One of the other autumn-flowering bulbs is Amaryllis belladonna, a striking plant with large, rich pink trumpet flowers. It needs a warm, sheltered spot but even then does not always bloom before the first autumn frost kills the flowers. It has been hybridised with nerdiness and you will find bulbs of Amarine at Nags Hall. These are as easy to grow as nerines but the flowers have broader petals and the plants are larger in all parts. They were bred for growing as cut flowers but they are good garden plants and I have them alongside my nerines and they are just as successful.
